Earth boring machine



April 23, 196s Filed No'v. 5, 1964 K. vC. COX

EARTH BORING MACHINE 7 Sheets-Sheet l Hls ATTQRNEY:

Aprinzs, 1968 K ,QX 3,379,264

' EARTH BORING MACHINE Filed Nov. 5, 1964 7 Sheets-Sheet INVENTOR. KENNETH C. COX BYv HIS ATT'OR NE YS April 23, 1968 K, C, Cox 3,379,264

EARTH omNG MAGHINE Filed Nov. 1964 v '/vsneets-she'et 1 HIS ATTORNEYS Apri 23, 196s K. C. cox 3,379,264

EARTH BORING MACHINE 7 Sheets-Sheet 4 HIS AT TORNEYJ 7 Sheets-Sheet 5 Filed Nov. 5, 1964 INVENTOR. KENNETH C. COX

HIS ATTORNEYS pril 23, 1968 K, C, CQX 3,379,264

EARTH BORNG MACHINE Filed Nov. 5, 1964 7 Sheets-Sheet 6 INVENTOR. KENNETH C. COX

\ w BY HIS ATTORNEY! '7 Sheets-Sheet 7 INVENTOR` KENNETH C. COX

HIS ATTORNEY5 K. C. COX

EARTH BORING MACHINE wwf i. .er a@ gr@ April z3, 1968 Filed Nov. '0, 1964 a@ wr United States Patent M 3,379,264 EARTH BQRING MACHINE Kenneth C. Cox, Sewickley, Pa., assignor to Dravo Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed' Nov. 5, 1964, Ser. No. 409,132 17 Claims. (Ci. 175--85) ABSTRACT OF THE DISCLOSURE its lateral support on the downhill side by the action of the cutter ahead, which is one increment inwardly and downwardly toward the center.

This invention is for a machine for digging or boring mine shafts, tunnels and similar large diameter openings in the earth.

The boring of mine shafts into or tunnels through the earth and the making of similar large diameter openings is a very slow and laborious operation, often requiring the presence of several laborers in the bottom of the shaft or excavation. Depending on the nature of the formations encountered in the operation, the procedure varies, but frequent interruptions are necessary to protect the workmen and remove them while blasting is being done.

The present invention involves the use of a plurality of cutting disks having wedge form peripheries, which are moved while being held against the working face under great pressure in concentric paths over the working face, but which are axially located in different planes so that the working face is of a cone-like configuration with the conical surfaces being desirably quite steep. The working face may be a positive cone in which the solid material projects into the excavation from the periphery toward the center, or a negative cone in which the working face is a cavity deepest at the center, or in large excavations it may have a combination of configurations. Because of this slope of the working face, the exposed rock formation does not have the lateral support at the exposed face capable of effectively resisting the wedging forces of the disk cutters that it has with present methods, so that the rock breaks out in generally larger fragments and boring progresses more rapidly. Using this method I prefer to initially remove material in a relatively small circular area either at the base or the center of the sloping face to form a lead opening and then to cut the surrounding bottom or working face on an angle or incline away from the lead opening in successive circular increments. In this process there is a perpendicular step between the initial lead shaft and the sloping or conical bottom or end wall. Cutters break and chip fragments from the rim of the lead opening of the sloping surface where, because of this step, there is no lateral support 3,379,264 Patented Apr. 23, 1968 for the formation next to the step and it breaks or chips away, with the cuttings falling out of the way. This in turn removes lateral support for the formation surrounding the part so removed at the rim of the step, and it in turn is broken out. This chipping away of the bottom or working face of the hole progressively away from the rim of the lead bore proceeds in concentric steps with the cuttings falling away, keeping the sloped Working face relatively clean and free. The boring of the lead shaft may be effected in increments as an advance operation, or its excavation may progress as the cutting away of the bottom or end wall occurs, but it is important that the cutting operation develop in concentric steps away from the lead bore or excavation.

For use in digging a vertical bore, the apparatus embodies a structure that may be lowered from time to time incrementally as the depth of the shaft increases, and which comprises a relatively stationary upper part and a rotary lower part having disk-like cutters thereon disposed to travel in concentric paths, with each path higher up the slope than the one it encircles. Provision is made for supporting the weight of the rotary lower part entirely on the disk cutters, and the effective weight of the rotary part may be increased or varied, as for example by tluid pressure means. The rotary lower part may have combined therewith a central boring head to advance the central lead excavation as the sloping bottom is cut away, or it may be designed for use where the central area is dug away in advance by other means. Provision is also made for removing the loose material as it collects.

In the boring of a tunnel, a somewhat similar rotary cutter head backed by an anchored frame structure is employed, the cutter head revolving about a horizontal axis instead of a vertical one, as in boring a vertical shaft.

An object of the invention is to provide an apparatus for earth boring in which the working face is maintained at a relatively steep slope of generally conical contour with the cutters thereby working against a formation from which lateral support has been substantially removed.

A further object of the invention is to provide an apparatus for shaft sinking and tunneling through earth formations which first cuts a circular lead opening and then cuts or breaks away the formation in successive concentric circles in axially-spaced planes.

A further object of the invention is to provide a novel earth boring or tunneling apparatus.

A further object of the invention is to provide apparatus for the removal of chips and cuttings continuously as the boring progresses.

These and other objects and advantages are secured by my invention as will be more fully understood from the following description in conjunction with the accompanying drawings, in which:

FIG. 1 shows partially in vertical section and partially in side elevation one form of apparatus embodying the novel apparatus for use in effecting the method, the view representing the apparatus in a shaft;

FIG. 2 is a view generally similar to FIG. 1, but showing a modified form of conveyor. Also, in this view an extension has been shown on one of the cutter struts only to illustrate how the apparatus may be utilized to excavate an opening on a larger diameter, in which case also a longer reach is shown for the side wall engaging p FIG. 3 is an end view, looking upwardly at the shaft digging apparatus of either FIG. 1 or FIG. 2, but on a smaller scale with the center drilling or conveyor mechanism removed and with the strut extension illustrated in FIG. 2 omitted; the view more or less schematically showing the disposition of the cutters wi-th the reference numerals in this view corresponding to those of FIG. 2;

FIG. 4 is a schematic view showing the system for removing the detritus with the machine of FIG. 2;

FIG. 5 is a somewhat simplified and schematic longitudinal section through a tunnel boring machine embodying my invention;

FIG. 6 is a top plan view of a portion of the machine shown in FIG. 5;

FIG. 7 is a view similar to FIG. 5 but showing a modified form of cutting head and showing a mechanical conveyor for removing the chips;

FIG. 8 is a somewhat schematic longitudinal sectional view of the boring end of still another modification of the rotating cutter head;

FIG. 9 is a front elevation of the cutting head shown in FIG. 8; and

FIG. 10 is a fragmentary view showing one of the lead cutters apart from the rest of the machine illustrating the manner in which it forms the initial cut.

Referring first to FIG. 1, it shows the general organization of one form of the invention, illustrating the mechanism in location in a shaft or bore where A indicates the portion of the shaft which has been excavated, and B is a centrally positioned pilot or lead bore of small diameter that in this figure is dug by conventional methods to a depth a few feet beyond the depth of the main shaft. The bottom C of the main shaft is funnel-shaped, sloping upwardly and outwardly from the rim D of the center opening to the full diameter of the shaft. It will be noted that the lead shaft B has vertical or nearly vertical side walls so that the earth formation at the rim D has no lateral support inwardly. The bottom C is at a relatively steep angle, preferably steeper than a normal angle of repose for the loose material being excavated and of the order of 45 or greater.

The method of digging involves cutting or chipping out the material beginning a short distance out from the rim D, forming a shoulder d in the bottom so that the material above this shoulder has no lateral support, and it in turn is broken or cut out, the cutting progressing annularly around the lead opening and in t-he same step-bystep attrition in small increments radially outwardly. The mechanism herein shown is `designed to dig in this manner.

The machine as shown in FIG. 1 comprises a fixed sleeve 2 about which are positioned radially-adjustable side braces 3 rcleasably holdingr the sleeve 2 against movement in the shaft. Typically there are four such braces equidistantly located around the sleeve, but only one of which may be seen in FIG. l. EachV brace comprises a xed casing 4 in which is telescopingly fitted a radiallymovable brace section 5 with a pad 6 at its outer end to bear against the side wall of the shaft. A hydraulic jack having a cylinder 7 anchored to the sleeve at 8 has a piston 9 which is connected at 10 -to the outer end of the brace section 5 and is provided for moving the brace section radially and holding it with pressure against the wall of the shaft.

The sleeve 2 has several vertical cylinders 11 attached to the side thereof and located between the side braces 3 so that in FIG. 1 only one of these cylinders is seen, but the others would be equidistantly spaced from the one shown. Each cylinder has a piston wit-h a downwardlyextending vertically-movable piston rod 12. Three or four such cylinders may be used.

There is a tubular column 13 slidably received in the 4 sleeve 2 with splines at 14 for holding the sleeve and column against relative rotation while permitting relative vertical movement. A rigid platform 15 is secured to the column below the splines. On this platform there are also several radially-adjustable side braces, equidistantly spaced, but only one of which can be seen in FIG. l. Here again, -three or four of these braces are desirable. Each brace, designated generally as 16, comprises a fixed casing 17 in which is slidably fitted a brace section 1S similar to the brace 3, but instead of a pad at its outer end, it has a roller 19 rotatable in a vertical plane about an axle 20. By means of these braces and the braces 3, the machine can be kept plumb and centered in the shaft.

Below the platform 15 there is a rotary shaft digging cutting head designated generally as 21 rotatable about an axis extending lengthwise of the shaft which is being made. It comprises a central sleeve 22 rotatable on bearing rings 23 about the lower end of the tubular column 13. There is a rigid platform 24 attached to and extending laterally from the top of this sleeve and spaced below the platform 15. A number of heavy diagonal struts 25 have their upper ends secured to this platform and their lower ends abutting against and secured to the lower end of the rotary sleeve 22. Typically, as shown in FIG. 3, there are four of these struts equidistantly arranged about the sleeve, but there may be more or less, desirably not less than two, and preferably not less than three. By the use of this arrangement the cutting head 21 has a plurality of radially extending struts projecting outwardly from the center and at an angle of at least 45 to a plane perpendicular to the axis of rotation and which define a cone of revolution when the head is rotated.

Secured to the undersides of the struts are brackets 26 at spaced intervals, and each bracket provides a bearing at 27 for a disk-like cutting wheel 28, the axis of rotation of which is radial to the sleeve 22, and `which is preferably inclined upwardly and outwardly at a slight angle to the horizontal such that the vertical plane of each cutter disk is inclined with respect to the horizontal and forms a substantially equal angle with the horizontal. Each cutter disk or wheel has a beveled cutting edge with a single bevel so that it is of generally chisel or wedge section -with the slope of the bevel from the outer face to the inner face of the wheel, the outer face being remote from the axis of rotation of the cutter head and of larger diameter than the inner one. By reason of this construction the outer fac'es of the disks are in planes that intersect both the cone of revolution and the struts at acute angles.

The cutter disks on each of the struts project from the cone of revolution described when the head 21 is rotated with their axes of rotation being radial to the axis of the cone of revolution and are so spaced along the struts that they all are in a single spiral helix around the cone of revolution. The spacing of the cutter disks on any one strut is a multiple of the radial distance between the innermost disk on one strut and the disk on the next succeeding strut in the direction of rotation of the head 21. The cutting wheels on the several struts are spaced so that each wheel around the cutting head moves in a separate circle positioned an equal increment radially and ver-- tically from the path of the adjacent ones. For example, in FIG. 1, the innermost cutter at the right moves about the rim D. The dotted outlines indicate the paths of the cutters on each of the other three arms when they rotate to the same position, and the rotating head moves in such direction that the next cutter out from the rim would be on thennext strut arriving at this position, the third critter' in dotted position would be on the third strut to reach this position, and the fourth cutter, also dotted, would be the fourth to reach this position. With four struts, the next or fifth cutter from the center would be on the same strut as the rst, and the succession would repeat.

Thus the action of each. cutter wheel follows in succession the cut made by the next cutter inwardly and downwardly. Each cutter works to break away an area which has lost its lateral support on the downhill side by the action of the cutter ahead, which is one increment inwardly and downwardly toward the center.

There is an annular ythrust bearing between the rotating table 24 and the fixed table or platform 15, and the rotating table 24 has an annular rack 31 thereon. A motor 32 drives a pinion 33 that meshes with this rack to effect rotation of ythe cutter head 21. The motor may be either an electric motor, hydraulic motor, or an air motor, and if necessary, more than one motor may be used. The motor should be one that does not present a tire hazard or a health hazard. The cutter wheels support not only the weight of vt-he rotary frame on which they are carried, but also the weight of the column 13, the platform 15, and all of the parts which it supports, the rollers 19 allowing the platform 15 and column 13 to move down with the cutter head. The weight of the conveyor, hereinafter described, is also supported on column 13 and is therefore carried on the cutter wheels.

The ends of the vertical piston rods 12 are attached at 34 to the stationary platform and serve a dual purpose. First, by energizing the cylinders 11 to exert a downward pressure on the piston rods, a downward force greater than the weight of the rotating head plus the weight of the column 13 and its parts is applied to the cutters. Secondly, when the pistons have been extended to their downward limit as they will be with the cutting away of the bottom of the shaft, the side braces 3 on the main sleeve 2 can be retracted and these cylinders used to lower the sleeve 2 and the parts carried thereby on the column 13 until the pistons 12 bottom in their cylinders, after which the lateral braces 3 are again set and the digging continued.

There is an operators cage 35 on the main sleeve 2 with a control console through which an operator can watch and control -the machine and lower it. Hydraulic pressure is used in the cylinders and jacks while air or hydraulic fluid is used for lthe motor 32.

Centrally positioned inside the tubular column 13 is a central column 36 constructed of a pair of back-to-back channel beams, the top of which projects above the top of the column 13, and the bottom of which extends below the bottom of the column 13. There is a pulley at the bottom of the column 36 at 37, around which passes the lower end of an endless bucket conveyor. There is a pulley at the top of the center of column 36 at 38 around which passes the upper end of this conveyor, and the conveyor is designated 39. A chute is shown at 41 for receiving material from the upper end of the conveyor and discharging it to a muck bucket 42 carried on a supporting structure 43 mounted on the stationary sleeve 2. A motor 44 is also shown on a platform attached to the sleeve 2 for driving a fluid pressure pump for operating vthe hydraulic cylinders and fluid pressure motors, which include motor 32. A reservoir is indicated at 44 for the hydraulic fluid used in the cylinders.

The column 36 along with its conveyor moves up and down with the column 13, being attached to the column 13 through supporting structures 4S at the top and the bottom of the column 13. The supporting structures 45 comprise cross bars 14 attached to the sides of channel beams 36 forming the rigid center of the conveyor with curved plates 14a engaged in journals 13 which permit the conveyor assembly to rotate about its vertical axis. The conveyor extends well below the lowermost cutter wheel 28 down into the pilot or lead shaft B. The cuttings that are broken out and chipped away by the action of the cutters fall into the pilot shaft B and are elevated from this shaft by the conveyor and discharged into the muck bucket. This bucket comprises a hopper-like receptacle having a discharge chute (not shown) for delivering material in-to a bucket that is raised and lowered from the surface of the ground, or the muck bucket itself may be raised and lowered by means of a cable (not shown), and the whole conveyor 39 can be rotated about its vertical axis so that as one bucket is filled the material can be charged into a second bucket 42 shown in dotted lines in FIG. 1. In this Way alternate buckets are used to transfer the detritus to the surface of the ground. An electric motor 46 is indicated at the top of -the column 36 for driving the conveyor.

The operation of the machine will be apparent from the foregoing description. The slope of the bottom C of the shaft is determined of course by the slope of the struts 25 for the cutters, and as before explained, each cutter wheel revolves in a circle concentric to the path of the others, but as here shown with no two cutters moving in the same path, and the cutters are separated by substantially equal increments both radially and vertically. The rotation of the cutter head assembly 21 on the bottom 23 will break and cut away or chip the earth, depending on the character of the earth formation and the beveled edges of the cutter Wheels exert a chiseling force to wedge into and break out hard formations, and this breaking out is made easier because of the progressive removal of the lateral support for the formation outwardly from the rim D. Actually, with this arrangement the cutting progresses in a stepped spiral over the slope from the unsupported rim of the lead or pilot excavation to the cutter wheel most remote from the rim. Considered in another way, the cutter wheels describe concentric helixes as they cut their way into the bottom or working face of the excavation. The downward or axial pressure on the rotating cutter head, the inclination of the working face at a relatively steep angle to the axis of the bore, and the wedge shape contour of the cutter wheel edges, plus the removal of the material progressively on a generally spiral path all contribute to the effective removal of the material. The cuttings of course fall away so that the area being cut, or the working face, keeps clear of the cuttings. If, in the progress of the excavation, the earth formation goes from a softer `to a harder stratum or vice versa, the cutter wheels inwardly or outwardly from the center may be working on different strata. After the softer material has been removed, all of the cutting force will then be concentrated on those cutter wheels working on the harder stratum, since the rotary head is a rigid unit, and axial movement of all of the cutters must proceed at the same rate. This same desirable concentration of force on fewer cutters may also occur in any hard formation where, because of the closer angular separation of the cutter wheels at the center of the head than at the periphery, the material may chip and cut away more rapidly than at the periphery. As the material is removed under the innermost cutting wheels, the weight and pressure is concentrated on fewer and fewer cutting wheels and thereby automatically increases the effectiveness of those still working.

The apparatus shown in FIGS. 2 and 4 is essentially the same as the one shown in FIGS. l and 3 with two important differences. In FIGS. 2 and 4 the rotating cutter head has a central boring bit for drilling the pilot' bore, and the detritus is removed by an air lift instead of a mechanical conveyor.

Referring to FIG. 2, 5t? designates the main sleeve corresponding to sleeve 2 of FIG. l. In this view there is shown for illustration only, one side of the machine having an extension on the cutter strut, while the opposite side has no such extension. In use however, the machine would always be symmetrical about its vertical axis. This is to illustrate how the machine may bore a large diameter hole at one elevation and a smaller one at another. There are here shown two of the four extensible side braces 51 which are used in this form, and which have hydraulic jacks 52 housed therein for setting the braces. For the smaller diameter hole the side brace 51 has the hydraulic jack bearing directly against the rear of the pad 53 as shown at the left side of this view, while, with the larger diameter bore, the end of the jack bears against an internal abutment inside the telescoping sleeve 53a on which the pad 53 is carried. The pad itself is shown slightly different but here unimportantly so from the corresponding part in FIG. 1. There is a tubular column 54 splined to slide in the sleeve t) as previously described, and at the lower end of this column there is fixed a platform 55. There are one or more, preferably three or four, vertical cylinders S6 corresponding to cylinders 11 of FIG. 1, but as here represented they are attached to an annular plate 57 secured to the sleeve 50 instead of being attached as shown in FIG. 1, but in arrangement and purpose are the same. Each vertical cylinder 56 has a piston and piston rod 58 extending downwardly therefrom and attached at its lower end -at 59 to the platform 55.

In this machine the rotary cutting head, designated generally as 60, is below the end of the tubular column 54. It has a central tubular body 61 at the top of which is fixed a platform or table 62 that is below the platform 55. There are diagonal struts 63 extending from the rim of this platform to the lower end of the tubular body at an angle of about 45 or steeper. Each of these struts has brackets 64 thereon on which are cutter wheels 65, as previously described, the cutter wheels being in staggered relation to each other on the several struts so that they travel in progressively greater concentric paths from the center outward with each cutter wheel on successive struts in the direction of rotation being a little further from the center than the one on the strut that leads it and a little nearer the center than the one that follows, and each cutter trails the one preceding by an arc so that cutters which travel in adjacent circles are angularly separated.

As Vhere shown one of the several cutter wheel struts is provided with an extension 63 at its outer end so as to lwork in line with the strut, or which may pivot at 66 to be moved into the dotted line position of FIG. 2. This extension has cutter wheels 65 yarranged like those of the strut to which they attach. This arrangement may be used for example where the bottom of a shaft is to be of less diameter than the top.

There is a central boring head 69 on the lower end of the tubular body 61 with cutters 70 similar to those used in 'a rotary well drilling tool for digging a shallow pilot bore at the center of the shaft so that the upwardlysloping bottom of the Shaft terminates at a vertical rim D as in FIG. 1.

There are centering braces 71 on the non-rotating platform 55 similar to braces 16 in FIG. 1 with rollers 72 'at the outer end of each for bearing against the side wall of the shaft and centering the lower end of the column 54.

There is a combination radial and thrust bearing 30 between the platform 55 and table 62, and table 62 has an annular rack 31 thereon. A motor 32 drives a pinion 33' that meshes with this rack to effect rotation of the cutter head 60.

The machine here shown utilizes a pneumatic conveyor for removing the detritus. This comprises a central conveyor tube 75 centered Within the cylindrical column 54. Its lower end terminates in an angularly-cut terminal 76 close to the pl-ane in which the cutters 70 are working. This terminal provides for the lateral in-sweep of air over the bottom of the bore so that it will be pick up the chips and ines and dust and carry this material into the tube. The conveyor tube rotates with the cutting and boring heads and is joined to a non-rotating pipe extending upwardly from the machine through a swivel which is designated generally at 77. t

The general organization of the machine is best shown in FIG. 4 where it will be seen that the non-rotating section of pipe 78 is connected to an expansion chamber 79. The expansion chamber may be mounted on the machine or it may be suspended by 'a cable at some point intermediate the surface of the machine and connected with the machine through some connection that permits relative vertical movement between the expansion chamber and the machine. As shown in FIG. 4 there is a flexible tube l86 between the pipe 78 and the expansion chamber 79. This tube terminates inside the expansion chamber near the top under a batiie 81 so that the material which is entrained in the air coming up through the tube strikes the baffle and falls to the bottom. The air free of most of its burden continues upwardly through a pipe or duct 82 to the surface where it may rst enter a dust chamber 83 and a positive displacement pump or centrifugal blower indicated schematically as 84.

The fan or vacuum pump on the surface is capable of drawing a high velocity stream of air through the conveyor tube so that air enters the lower terminal 76 at high velocity. This is capable of picking up the cuttings even to a comparatively large diameter and carrying them into the expansion chamber. However if the machine is stopped for a period of time, water may accumulate in the bottom of the shaft, and this would prevent the circulation of air. Consequently there is provided in the rotating head laround the tubular body 61 a pumping system including an air motor which drives a pump 91. This pump has an inlet pipe 92 that extends down through the central boring head 69 and terminates near the bottom of the shaft. This pump discharges into an outlet pipe `93 that extends upwardly parallel with the conveyor tube 7S to a swivel construction 96 forming part of the swivel arrangement 77 whereby the pipe 93 f may rotate with the tube 75, but the discharge from the pipe 93 is carried into a non-rotating pipe 97 that in turn discharges into a high pressure pump (not shown) through which the water is pumped to the surface. For operating the air motor 90 there is provided an air supply pipe 98 leading from a second swivel connection 99, also forming part of the overall joint at 77, through which air under pressure is supplied from a non-rotating pipe 100. The pipe 100 leads to an air supply system (not shown) controlled from the operators console 101. This console is positioned near the top of the unit above a platform 102 attached to the upper end of the sleeve S0. The swivel connections 96 and 99 are of a known construction and form no part per se of the present invention.

On the platform 162 there is a motor .103 which provides hydraulic pressure for the control of t-he several jacks, and which may also operate a pump for supplying air pressure through the pipe 98 `to the motor 96. These pumps are of conventional construction and in themselves form no part of the invention.

The expansion chamber 79 has a discharge chute 79a over the outer end of which there is a ti=ghtly-titting movable closure 7917. This closure is opened from time to time to allow material from the expansion chamber to be discharged into a muck bucket (not shown), but when t-he gate or closure is normally closed, it forms a seal against the substantial iniiow of atmospheric air.

The water pump is usually needed only when the machine has been shut down for a time sutlicient to allow water to accumulate. In operation, after the removal of accumulated water, the normal flow encountered in a shaft may be carried out by the pneumatic conveyor with the dust and cuttings.

In both embodiments of the invention here described there is a rotary cutter frame having a series of cutter wheels of disk-like shape so arranged as to travel in concentric circles. One cutter wheel nearest the lead bore is a lead wheel, and each succeeding wheel is angularly located ybehind the one lahead, with preferably no two wheels in adjacent concentric circles being side-by-side. Each cutter wheel and the circle in which it revolves is in a plane axially spaced from the one ahead so that they move on and cut a circular sloping or conical surface.

The use of a pneumatic conveyor for the removal of cuttings is especially desirable since it induces a downdraft of air toward the working face, carrying the dust which is a necessary incident to an operation of this kind continuously away, so that the operator with the aid of lights, not shown but customarily used in underground and deep shaft boring, can see the working face and the functioning of the apparatus and the removal of the dust also avoids a health hazard. The pneumatic conveyor, moreover, enables the lead bore to be dug along with the sinking of the sh-aft floor, whereas a bucket or flight conveyor is less adaptable, and a screw conveyor is less adaptable than the pneumatic one.

In the machine shown in FIGS. 'and 8 the general organization of the machine for boring tunnels is shown, and except for the difference in the boring heads is the same, and corresponding reference numerals have been used to designate corresponding parts.

Referring irst to FIGS. 5 and 6, the 4boring head is much like that shown in the vertical machine where the lead opening or advance cut is at the center and the solid walls slope rearwardly toward the excavated shaft.

In this view, 114) is the movable bed frame of the machine. A structure 111 houses a central gear 112 and the structure .111 supports one and preferably two or more motors 113. These lhave pinions 114 meshing with the gear 112. The gear 112 is xed on a central shaft 115 mounted in bearings 116 in a fixed outer sleeve 117 attached to the structure 111.

At the forward end of the shaft 115 is secured a hub element 118. This is attached to a sleeve-like cylindrical hub 119. The back of the hub 119 is welded or otherwise attached to a circular back plate 120. At the forward end of the hub 119 is a fixed cutter head 121 on which are central cutters 122 for cutting a lead opening or advance cut E in the center of the working face.

A plurality of struts 123 extend to the periphery of the plate 120 at an acute angle to the longitudinal axis of the machine. The struts have cutter disks 124 positioned therealong in staggered relation to the cutter disks of adjacent struts, as previously described.

The arrangement is such, therefore, that when the gear 112 is rotated, the boring head comprising the plate 120 and the parts forwardly of it rotate.

There is a horizontally-extending transverse anchoring frame structure 125 which has a wall-engaging shoe 126 at each end thereof that is extended and retracted by a f'iuid pressure cylinder 'and piston assembly 126m The sleeve 117 passes through the structure 125, being sli-dably fitted in a ring 128 that has an arcuately convexed outer surface fitted within a concaved annular collar 129 secured in the cross frame 125. The cross frame has depending iianges 130 that straddle a slide block 130a that is slidably set on a slideway 131 on the forward end of the bed frame 11G. This end of the bed frame has shoe element 132 positioned below it and which may be raised and lowered by a fluid pressure jack 133. At the rear end of the bed frame there is an extension 134. A cross beam 135 is suspended from this extension through a lluid pressure jack 136. There is a shoe 137 at each end of this beam.

By operating the jack 136 the rear end of the mac-hine may be raised or lowered with the pivoting taking place between the transversely-curved ring 128 and the bearing ring `129 to Igive directional connection to the machine in a vertical direction. Horizontal guidance can be effected through shoes 126 and their jacks 125:1.

The shoe 132 is slidable on the fioor of the tunnel, 'as are the two shoes 137 at the rear of the machine, while the shoes 126 on the end of the cross frame structure clamp this structure against the side walls of the tunnel as the bed frame moves forward relative to it, the fixed sleeve 117 sliding through the ring 128. This relative movement of the bed frame is effected by a p'air of uid pressure cylinder and piston units or jacks 140. One of these units is located at each side of sleeve 117 and has its forward end pivotally attached to a plate 141 at the forward end of the sleeve 117 Iand its rear end secured at 142 to a bracket 143 extending rearwardly from the transverse anchoring frame structure 125.

There is a roof support indicated lgenerally at 14011 which has a roof engaging plate 1410 curved to lit against the roof of the tunnel and connected to a longitudinal frame member 142a on the structure 111 by two pairs of links 143m Vertical adjustment of the roof support is effected by a hydraulic cylinder 144a pivotally connected to a crossbar V145i: adjacent the lower end of the rearwardmost pair of links. The hydraulic cylinder 144i: has a piston rod 146a pivotally connected to a crossoar 147a adjacent the upper ends of the forwardmost pair of links 142m. The arrangement is such that by extending or retracting the piston 1464 through conventional liuid pressure controls (not shown), the two pairs of links 143a may be raised or lowered. The roof support is of known construction and forms no part per se of the present invention.

It will be seen that the cross frame structure 125 is essentially the counterpart, at least in function, of the platform 102 of FIG. 2 with anchoring shoes 4at its sides, and the ring 128 through which sleeve 117 slides is the same functionally as sleeve 50 of FIG. 2. The jacks 140 correspond in function to jacks 56 of that figure.

Therefore, with the parts in the position shown in FIGS. 5 and 6, the clamping shoes 126 on the ends of the cross frame 125 are firmly set against the side walls of the tunnel. The sliding supporting shoes 132 land 137 are adjusted to the correct height. The cutting head is then rotated and fluid pressure is applied to the jacks 141) to thrust the revolving head and the bed frame and parts carried thereon forwardly and to continue this forward thrust until the jacks 141) are fully extended, when the position of the cross frame 125 relative to the bed of the machine will be that indicated by the dotted line, but it should be understood that the machine has moved forward and the cross head has not moved at all. At this time the clamping shoes 126 are retracted, the fluid pressure jacks are operated in the reverse direction to then pull the anchoring frame structure toward the cutting head, restoring the relation of the parts as shown in the drawings. The clamping shoes 126 are again set and the operation is repeated. Here, as with the vertical machines first described, the cutters move in concentric circles with the cutters 4being effective in -axially separated planes to cut an inverse cone in the working face.

The chips or cuttings may be removed in various ways. In FIG. 5 I have shown a pneumatic conveyor, like that previously described, the conveyor tube being designated 145. It terminates at 146 close to the periphery of the revolving plate 120. All of the chips and cuttings will 'fall into the area adjacent this teirninal. Mechanical conveyors may, however, may be substituted or used in conjunction with air.

The arrangement shown in FIG. 7, as heretofore indicated, is much the same as that shown in FIGS. 5 and 6, except that in this figure the cutting head is designed to form an outwardly-projecting cone on the working face instead of a reverse cone as in FIG. 5. As seen in FIG. 7, the working face includes a solid portion projecting axially into the bore toward the axis of rotation of the cutter head. There is some slight modification of the hub structure at the end of the rotating shaft in this case, and in FIG. 7 this hub structure is designated generally as 150. It is secured to the rear of a rotating plate 151 corresponding generally to the plate of FIG. 5. This plate 151 is generally circular as indicated by the dotted line at 152 but has radially extending projections 153 to each of which is secured a scoop-like bucket 154. The back face of one such bucket receding from the viewer and being shown in elevation in FIG. 7, while on the projection 153 at the top, the bucket which is approaching the viewer is in vertical section, so that what is the bottom plate of the bucket in the lower view is seen as a double cross-hatched line at the top and the end walls are also in section. The plate 151 may thus be regarded as a disk with radial spokes and material that is dislodged by the cutters moves back between the spokes to be gathered into the buckets and elevated. Projecting forwardly from the extensions 153 are a series of struts 155 that parallel with the axis of rotation. On the outer ends of these struts 155, of which there are a plurality, are roller bits 156 for cutting the lead penetration F in the working face of the mine at the periphery of the bore. A framework of supporting plates 153 extends from the struts 155 at an angle of about 45 or greater to the axis of the machine to a central structure 159 at the center of the plate 151. Along this frame 158 are distributed cutters 169` arranged in the same concentric staggered relation as the cutter arrangement in previous figures, but since the cutting occurs with these disks from the center outwardly, the wedge-shaped edges of the cutters are reversed from the arrangement shown in the other iigures.

At the very center of the front of the plate 151 there is a socket 161 which receives the shank of a central boring cutter assembly 162 similar to that used in rotary rock drills.

With this arrangement, as the cutter head rotates and is forced axially against the working face of the mine, the cutters rolling over the periphery of the working face in the manner previously described tend to cut out or break the material progressively from the rim of the lead eut yF inwardly toward the center. The chips fall to the bottom ot the tunnel where, as the machine moves forwardly, they are scooped into the buckets 154 and retained in the buckets as the buckets travel upwardly. What was the open top of a bucket at the bottom of the tunnel becomes a downwardly-directed opening 163 in the uppermost position of a bucket. The material falls through this opening 163 into a non-rotating hopper structure 164 mounted on a non-rotating central support 165. A chain conveyor schematically indicated at 166 moves the cuttings as they fall onto the conveyor along a conveyor chute 167 in a manner well understood in the art.

The pneumatic conveyor system previously described may be used in lieu of this mechanical system, or this mechanical system could be used in the construction shown in FIG. 5, or both systems may be used with the heavier parts being removed mechanically and the suction used only for the clean-up of iines.

In FIGS. 8 to l0 there is disclosed still another modiiication particularly applicable to situations Where large diameter tunnels are being bored. Here the cutting head is designed to form a central positive cone on the working face surrounded by a cavity `having walls which slope in the reverse direction so that in cross section the working face has the general shape of the letter W. As seen in FIG. 8 the working face includes .a solid tirst portion projecting axially into the bore toward the axis of rotation of the cutter head and includes another portion which surounds the rst portion which slopes from the base of the first portion toward the periphery of the bore. In the construction shown in FIG. 8, the machine has a fixed plate 160 that can be advanced toward the working face as in the other machines. There is a rotary head structure designated generally 161' that includes an annular rack 162. There are one or more motors 163' on the back of the plate 160 which drive the pinions 164 that mes-h with the annular rack 162 to rotate the head. The head itself includes a supporting frame structure 165. There are a series of struts 166', usually four, that extend from the 'periphery ofthe -frame 165 angular- 1y forward. The forward end of each strut 166' is connected to a rearwardly-sloped strut 167'. Four of the struts 167 are equidistantly spaced around the rotating head and are joined together at 168i forming the center of the revolving head. The struts 166 and 167 carry cutters 169' similar to those previously described, but the taper on the edge of the cutters on the struts 166 are reversed with respect to those on the struts 167'.

In one quadrant of the rotating head there are two forwardly-extending rigid posts 170` which carry speciall?. ly formed cutters 171, one of which is reversed with respect to the other, which cut the lead opening 172 in the working face inwardly from the cutter 169 that is deepest in the working .tace of the tunnel. There may be a similar pair of reversed cutters like these in a second quadrant, preferably the one opposite the quadrant in which the rst pair is located.

In this construction as in all of the previous constructions, the cutters on t-he respective struts are staggered so that they move in different concentric circles. They are all designed to work radially away from the lead opening, being progressively located in different transverse planes so that they cut on a slope or incline. The particular advantage of the W shape is that the faces being cut can be steep enough for the chips to fall away by gravity without the cutting head being excessively long in an axial direction, as it would be in a shaft of very large diameter, and the cutting head was arranged as shown in the preceding figures.

While I have shown and described certain speciiic embodiments of an apparatus embodying my invention and for the practice of the method of earth excavating, it will be understood that this is by way of illustration and that various changes and modications may be made therein under the scope of the following claims.

I claim:

1. An earth boring machine having a rotary frame, rotatable about an axis extending lengthwise of the bore which is being made, said rotary frame having a plurality of rotatable disk-like cutter wheels having wedge form peripheries, said cutter wheels mounted on and projecting forwardly from ythe frame in such manner that they move in concentric circles about the axis of rotation of the frame and so arranged in a single spiral helix such that the cutter wheels in adjacent concentric circles are angularly spaced yin a regular progression rearwardly from the one ahead when the frame is rotating and with the concentric circles described by the cutter wheels being axially displaced rearwardly in regular progression from one another to move on and effect cutting of a conical working face in the bore, each of the cutter wheels having inner and outer faces with the outer face of each cutter wheel being remote from the axis .of rotation of 4the rotary frame, the outer `faces of the cutter 4wheels being in planes that intersect both the conical working face andthe rotary frame at acute angles of the excavation.

2. An earth boring machine as dened in claim 1 in which the rotary head has a boring cut-ter projecting axially ahead of all the cutter wheels for boring a lead excavation in the working face of the bore concentric with the conical working face on which the disk-like cutter wheels move.

3. An earth boring machine as dened in claim 1 in which the rotary frame comprises a plurality of inclined struts disposed at equal angles about and secured to a rotatable support, the cutter wheels being mounted on said struts at spaced intervals and starting with the cutter wheel on one support nearest the center of rotation, the cutter wheels on 4the several s-truts being progressively further removed from the frst so that each cutter wheel describes a concentric circle about the axis of rotation larger `than the one which it succeeds in the progression, and by reason of the angularity of the struts in a plane.

4. A Vshaft sinking apparatus comprising a main sleeve member,

laterally extending jack means on the main sleeve member for bracing and holding it lfixed in the shaft being dus,

a column splined in said main sleeve member for vertical movement therein but non-rotatable with respect thereto,

a platform structure on the lower portion of said column,

jacks on said platform having rollers at the outer ends thereof for centering the lower end of said column 13 in the shaft while permitting it to move down as excavation progresses in the bottom of the shaft,

a rotary cutter head the full diameter of the shaft `mounted about the lower end of said column and rotatable about a vertical axis passing upwardly through said main sleeve member,

the cutter head having a plurality of rotatable cutter wheels thereon wi-th their axes of rotation being radial to the axis of rotation of the cutter head and being inclined at an angle to the horizontal such that the vertical planes of the cutter wheels form substantially equal angle-s with the horizontal, the cutter wheels being positioned yon said cutter head in such manner Ithat they move in concentric circles about the axis of rotation of the cutter head and so arranged that the cutter wheels in adjacent concentric circles are angularly spaced in a regular progression rearwardly from the one ahead when the cutter head is rotating and with the concentric circles described by the cutter wheels being axially displaced rearwardly in regular progression from one another to define a sloping circular shaft bottom when the cutter head is rotated,

cooperating means on the platform and the cutter head -for rotating the cutter head,

and a thrust bearing effectively interposed between the platform and the cutter head whereby the cutter head supports the non-rotatable column and the platform.

5. A shaft sinking appara-tus as defined in claim 4 wherein there is a conveyor in said column effective for conveying cuttings from the central area of the rotary cutting head to a level above the top of the main sleeve member.

6. A shaft sinking apparatus as defined in claim 4 wherein there is a conveyor in said column effec-tive for conveying cuttings from the central area of the rotary cutting head to a level above the top of .the main sleeve member, said conveying means comprising a duct extending from the bottom of the shaft near the center of the rotary cutting head to an expansion chamber located at a level above said main sleeve member, and means for drawing a high velocity a-ir stream from the bottom of the shaft up through the duct and int-o the expansion chamber to effect ventilation of the bottom of the shaft and remove the cuttings.

7. Shaft sinking apparatus as defined in claim 6 wherein the duct is supported for rotation with the rotary cutting head and has an angular lower terminal, .the duct connecting with the expansion chamber through a swivel and non-rotating tube operatively interposed between the duct and the expansion chamber.

8. A shaft sinking apparatus as defined in claim 4 ywherein there is a conveyor in said column effective for conveying cuttings from the central area of the rotary cutting head to a level above the top of the main sleeve member, said conveying means comprising a duct extending from the bottom of the shaft at the center of the rotary cutting head to an expansion chamber located at a level above said main sleeve member, means for drawing a high velocity air stream from the bot-tom of the shaft up through the duct and into the expansion chamber to effect ventilation of the bottom of the shaft and remove the cuttings, and separa-te means on said apparat-us including a second duct terminating near the bottom end of the Afirst duct and a pump connected with the second duct for removing accumulated water inthe shaft after opera-tion has ceased and `when operations are then resumed to a level where the lower end of the first duct is uncovered.

9. Shaft sinking apparatus as defined in claim 4 wherein there is a boring head centered on Vthe rotary cut-ter head which projects beyond the lower end of the rotary cutting head for cutting a lead bore in advance of the cutters .on the cutting head.

10. Shaft sinking apparatus as defined in claim 4 in which fluid pressure cylinder and piston units are operatively interposed between the main sleeve member and the platform on said colu'mn for lowering the main sleeve member on the `bottom of the column after the column has moved down relatively to the main sleeve a predetermined distance.

11. Shaft sinking apparatus as defined in claim 4 in which fluid pressure cylinder and piston units are operatively interposed between 'the main sleeve member and the platform on -said column for lowering the main sleeve member lon the bottom of the column after the column has moved down relatively to the main sleeve a predetermined distance, the main sleeve having a platform 'thereon providing a station for an operator who controls the apparatus.

12. Shaft sinking apparatus as defined in claim 4 wherein said column c-omprises a -tube concentric with the axis of rotation lof the rotary cutter head about which the main sleeve member is slidably fitted.

13. An earth boring machine comprising a supporting structure arranged to be incrementally moved progressively into the bore as the bore progresses with means thereon for releasably holding it against movement in the bore,

a rotatable cutting head at the entering end of the supporting structure rotatable about an axis extending lengthwise of the bore Iwhich is being made,

said cut-ting head having a plurality of radially extending struts projecting outwardly from the center `and at an angle of a-t least 45 to a plane perpendicular to the axis of rotation, said struts defining a cone of revolution when 'the head is rotated, and a plurality of rotatable cutter disks having wedge form peripheries, said cutter disks mounted on and projecting forwardly from each of said struts with said cutter disks being s-o spaced alon-g said struts -that they all are in a single spiral helix around the cone of revolution, each of said cutter disks having inner and outer faces wi-th the outer face of each disk being remote from the axis of rotation of said cutter head, said .outer faces being in planes that intersect =both the lcone of revolution and said stru-ts a-t acute angles.

14. The earth -boring machine as set forth in claim 13 wherein the disks have beveled edges such that the diameter of the outer face of the disks is larger than that of the inner face of said disks.

1'5. The earth boring machine as set forth in claim 13 which includes means for exerting press-ure against the head to urge the head against an earth formation on which the cutter disks bear.

16. An earth boring machine having a rotary cutter head rotatable about an axis extending lengthwise of the bore which is being made, said cutter head havin-g a plurality of rotatable cutter wheels thereon with their axes of rotation being radial to the axis of rotation of said cutter head, said cutter wheels being positioned on said cutter head in such manner that they move in concentric circles about the axis of rotation of said cutter head in such manner that said cutter wheels in adjacent concentric circles are angularly spaced in a regular progression rearwardly from the one ahead when said cutter head is rotating and with the concentric circles described by said cutter Wheels being axially displaced rearwardly in regular progression from one another to define a sloping working face when the cutter head is rotated which working face -includes a solid portion projecting axially into the bore toward the axis of rotation of said cutter head.

17. An earth boring machine as defined in claim 16 in `which the cutter wheels are also arranged to define another portion of the working face which surrounds said rst mentioned portion and which slopes from the base of said rst mentioned portion toward the periphery of the bore.

References Cited UNTED STATES PATENTS Carlson 175-98 X Brutus 175-333 Newsom 175-230 X B011 175-334 Ramsay 175--94 Robbins 175-333 X Robbins 175-94 X Robbins 175--376 'X Seifert 175-351 X Persson 175--94 Robbins 175-376 X 16 7/1965 Jacks-0n et a1. 175-95 2/1966 Robbins et al. 299-56 5/1966 Brown 175-99 X 1/ 1907 Guttzeit 175-333 10/'1908 Wittich 175-102 3/19114 Kitsee 175--94 8/1920 Blackwell 175--98 FOREIGN PATENTS 4/1960 Australia.

9/1958 Great Britain.

8/ 1960 Great Britain.

CHARLES E. OCONNfELL, Primary Examiner.

15 I. A. CALVERT, Assistant Examiner. 

